It is common to use connectors of plastic or other dielectric materials to hold or carry terminals used to make electrical connections in various environments, including automobile wiring. The connectors add structural integrity to the terminal connection, furnish additional terminal connection holding power and can provide mounting convenience. A typical arrangement may include a complemental set of male and female plastic connectors with a detent, position guide and/or snap lock feature which permits the connectors to be coupled to one another and to remain coupled during normal use. Each connector is adapted to receive an electrical terminal, through one opening into an internal cavity. The cavity is usually designed with tolerances which permit a certain amount of lateral play between the terminal and the connector.
One known connector includes a sidewall which is slotted or perforated to provide a laterally resilient tab or “lance” having a half-arrowhead type of cam surface on the interior thereof. The barb on the half-arrowhead ramps up away from the terminal-receiving opening such that when the terminal is inserted through the opening, the side of the terminal engages the cam surface of the lance and pushes the lance outwardly until the body of the terminal passes the cam surface on the lance, at which time the lance snaps back in behind the terminal body to prevent the terminal body from being withdrawn. If the lance is externally accessible, it can be flexed outwardly with a small blade to allow removal of the terminal. This is common in well known arrangements; see for example U.S. Pat. No. 6,491,542, “Combined Connection and Terminal Position Assurance Structure for Vehicle Wiring Connectors,” assigned to Yazaki North America.
It is also known to provide terminal position assurance (TPA) features on plastic connectors. In general, TPA's involve an additional component which is snapped onto or otherwise secured to the connector body in such a way that they cannot be moved to the locked or set position unless the terminal is fully inserted into the connector body; i.e. a partially-inserted connector urges the lance outwardly enough to interfere with moving the TPA to the locked or set position. The aforementioned '542 patent shows a TPA.